Just a few weeks ago, the Cubs indicated that Jake Arrieta would have his first spring start delayed, in part out of a desire to place some limit on his workload this season. Arrieta has made it clear that he’s fine with this, and that he sees the value in some mindfulness about his workload in 2016. Now, there’s a few ways of looking at this. Recently, our own Ryan Davis detailed the strain that Arrieta’s use of the “slutter” might put on his elbow, and that’s certainly worth keeping an eye on. However, given that Arrieta also pitched nearly 100 more innings in 2015 than he did the previous year (which in itself was a 40-pitch increase) pitch choices aren’t the only things worth monitoring when it comes to Arrieta.
The idea behind limiting a pitcher’s total innings in a season has a bit of an unclear history. Not very long ago, pitchers did not have the restraints on them that are often in place today, and definitely didn’t have clear innings caps like what the Washington Nationals put in place for Stephen Strasburg just a few seasons ago. In fact, pitchers of lore often threw far, far beyond what modern hurlers do. For instance, a personal favorite of mine, Old Hoss Radbourn, threw nearly 700 innings in his 1884 campaign. It should be noted that he never came close to that total in his career afterward, and it probably helped to spell the downward trajectory of his career. Really, his best two years were 1883 and 1884, in which he threw about 1,300 innings combined. And, of course, the game was different then.
The development of specific pitch count limitations is a bit more clear, however, as a 1998 Baseball Prospectus article put forth the idea that the number of pitches might be having a negative impact on pitcher health when not carefully monitored. In 2010, Anna Floch illustrated the change in pitch count philosophy as it was increasingly impacting minor league pitchers. In her piece, she noted that the “magic number” for a start is somewhere around 100 pitches, which is a number we’ve come to expect and understand in the years since. Not everyone agrees fully with this idea, however, as Perry Arnold claimed in 2009 for Bleacher Report that pitchers were just simply being “babied” from the lower ranks of the minor league organization to the top, and simply were not learning to go deep into games. For Reuters in 2012, Ivan Oransky posited that pitch counts aren’t really the cause of injury in young pitchers, and Nolan Ryan chimed in a few years ago in agreement.
Ultimately, it’s difficult to find a consistent understanding of what works and what doesn’t in terms of monitoring pitch counts and innings thrown, but in terms of fatigue, the Cubs are clearly looking to try and avoid tiring out their star pitcher with too much work during the course of spring training and the regular season. They intend to play deep into October, after all. While the Cubs may not strictly limit Arrieta’s innings, a closer monitoring of his pitch counts and how deep into games he’ll go this year is probably going to happen. In an article on ESPN a few weeks ago, he acknowledged a personal desire to finish the games that he started in 2015: “Last year my mindset was I want the eighth or ninth inning every time out.” He went on to admit to feeling “a bit out of gas” in his last two starts of the postseason.
As I mentioned earlier, Arrieta spent a lot more time on the mound last season than he ever has before, and this creates a bit of uncertainty about how he will react going forward. To attempt to get an idea of how this has affected players in the past, I turned to the research team at Baseball Prospectus for some help with a bit of precedent in this regard. Here’s a list of pitchers who have seen 100+ innings spikes since 2000:
|Pitcher||Name||Year 1||IP||Year 2||IP|
For the sake of keeping these comparisons as similar as possible (though they can’t be exact, of course), let’s look at how the following year went in terms of each pitcher’s WARP and DRA:
|Roy Oswalt||2005||241.7||3.5 (down from 5.5 in 2004)||4.16 (up from 3.64 in 2004)|
|Woody Williams||2004||189.7||1.4 (down from 4.5 in 2003)||5.11 (up from 3.87 in 2003)|
|Randy Johnson||2005||225.7||4.8 (down from 8.8 in 2004)||3.58 (up from 2.49 in 2004)|
|David Wells||2003||213||2.5 (down from 2.9 in 2002)||4.62 (up from 4.33 in 2002)|
|Chris Capuano||2006||221.3||3.1 (up from 1.1 in 2005)||4.50 (down from 5.04 in 2005)|
|Adam Wainwright||2010||230.3||5.4 (up from 3.5 in 2009)||3.23 (down from 4.16 in 2009)|
That’s fairly inconclusive. For comparison’s sake, in 2015, Arrieta threw 229 innings and was a 7.4 WARP pitcher with a DRA of 2.31. This was up from 156.7 IP, 4.7 WARP, and 2.33 DRA the previous year.
The bottom line is that it’s not obvious just what will happen with Arrieta in 2016. PECOTA projects him to look at lot more like he did in 2014 than he did last year, which might disappoint some people, but it’s worth noting that he was a very good pitcher that year. And in looking at some of these prior examples of pitchers who have seen sudden jumps in their innings totals, some saw dips in performance the following year and some continued to improve. Which tell us … what? Not much, I think. The sample sizes are so small, and human beings so idiosyncratic, that a lot of this will come down to Arrieta himself, and how he approaches the season. That stuff matters. About five months ago, Sahadev Sharma wrote about the intangibles that go into these decisions sometimes, and those’ll be especially important for Arrieta, who’s honed the mental side of his game to a fine point. Which is why, in the end, the most important thing pointing in a positive direction for Arrieta might be that he has already bought into the idea that he needs to keep himself rested and ready. That could be enough.
Lead photo courtesy Mark J. Rebilas—USA Today Sports.